Caused By: java.sql.SQLIntegrityConstraintViolationException: ORA-00001: unique constraint (APPS.PS_TXN_PK) violated oracle.jbo.PCollException: JBO-28030: Could not insert row into table PS_TXN

This might happen when you deploy another application in the same server environment where the already defined Transaction Id is again attempted to add in the existing table and violates the unique identity constraint. Reset the sequence number.

Other Useful links for the topic in discussion

http://docs.oracle.com/cd/E17904_01/web.1111/b31974/bcstatemgmt.htm#ADFFD1306

http://docs.oracle.com/cd/E17904_01/web.1111/b31974/bcstatemgmt.htm#ADFFD1307

http://docs.oracle.com/cd/E17904_01/core.1111/e10105/repos.htm#ASADM11531